build(deps): bump diesel-async from 0.7.4 to 0.8.0

Bumps [diesel-async](https://github.com/weiznich/diesel_async) from 0.7.4 to 0.8.0.
- [Release notes](https://github.com/weiznich/diesel_async/releases)
- [Changelog](https://github.com/weiznich/diesel_async/blob/main/CHANGELOG.md)
- [Commits](https://github.com/weiznich/diesel_async/compare/v0.7.4...v0.8.0)

---
updated-dependencies:
- dependency-name: diesel-async
  dependency-version: 0.8.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>